Please open-source the official Flashbots builder, or document its algorithm

Dear Flashbots team,

According to this article, the Blockbuilding Algorithm will change after The Merge. Bundles are no longer ranked by effective gas price, and other transactions may land between bundles. The new algorithm is said to be designed to produce the most profitable block possible.

However, “the most profitable block” is only in theory, if you simulate all possible combinations of bundles and mempool transactions. The exact algorithm is not documented. Flashbots released an example builder i.e. boost-geth-builder, but according to what Flashbots crew metachris#2573 said in Flashbots Discord, it is just a reference builder implementation and the official Flashbots builder is a separate closed source implementation.

It is crucial for us searchers to know what the exact bundle merging algorithm is, because we need to know how to optimize our strategy and debug our bundle landing. Searchers don’t like the builder to be a blackbox.

There are only 10 days until The Merge as I write this. Searchers need time to change their bots, preparing for the new algorithm. Therefore, I hope the Flashbots team could make the official Flashbots builder open-source, or document its exact algorithm in details.

A searcher

Hello @zzh, thanks for coming.

We are discussing internally about making the builder free software. And we are testing the algorithms.

I don’t think we will have time to package, document, and present everything for next week. Our main focus right now is blockchain liveness, security, and stability.

I know this transition period will cause disruption and discomfort. That’s why we are opening these forums, so we can get together and make sure that what we are building makes sense long-term for everybody involved and that everybody can contribute. These thoughts you shared are very appreciated.

Some of the things that are in my mind:

  • Do all the builders have to be free software, or only flashbots’.
  • If the builder is free software, should the searcher bots be free software too? Like, consciously think what is the value of information hiding, if there is any.
  • What information should the builders provide to make for a nice searcher experience. Like, in documentation, source code, and API.

What do you think?

Answering all of this will take a while :slight_smile: We will come back with progressively better answers soon.